1. Field of the Invention
The present disclosure relates to rotorcraft external load control, and more particularly to determining cable angle in cables coupling external loads to rotorcraft.
2. Description of Related Art
Rotorcraft, like helicopters, commonly maneuver with external loads such as sling loads, sonar dipping buoys, mine sleds, etc. The external loads generally couple to the rotorcraft through a lifting device and are exposed to the rotorcraft operating environment. The environment typically exerts forces on the external load, such as from wind, wave action, and ocean currents, and compensation may be required in order for the rotorcraft to maintain the external load in a desired disposition. Since forces exerted on the load can influence rotorcraft performance and/or the integrity of the external load, rotorcraft aircrew generally monitor the external cargo during flight, typically through a measurement device associated with the lifting device. For example, the angle of the lifting device relative to the rotorcraft may be acquired during flight and feedback to avoid undesirable lifting device deflection. The effectiveness of measurements can be influenced by the measurement location, accuracy of the measurement device, and the relationship of the measurements to the true disposition of the external load relative to the rotorcraft.
Such conventional methods and systems have generally been considered satisfactory for their intended purpose. However, there is still a need in the art for improved systems and methods for controlling rotorcraft external loads. The present disclosure provides a solution for this need.